Magnetic Therapy: Plausible Attraction? by James D. Livingston
A double-blind study at Baylor
College of Medicine, published last November in Archives of Physical
and Rehabilitation Medicine (Vallbona 1997), concluded that permanent
magnets reduce pain in post-polio patients, and the results were heralded
in The New York Times and on Bryant Gumbel's Public Eye. PBS's Health
Week and Time magazine recently reported on the growing use of magnets
by champion senior golfers and other professional athletes to relieve
pain. Magnetic pain relief products are now sold in many golf shops,
and ads for them appear in national golf and tennis magazines. Long
a significant component of the health industry in Japan and China, magnetic
therapy is becoming a more and more visible part of the alternative-medicine
boom in the United States and Europe. Is it all just hokum, as many
previously assumed, or is magnetic therapy becoming scientifically respectable?
Early History
For thousands of years, wonder and magic were associated with the mysterious
forces exerted by natural magnets -- magnetite-rich rocks, today called
lodestones. Many trace magnetic therapy back to Paracelsus (1493-1543),
a physician and alchemist who reasoned that since magnets have the power
to attract iron, perhaps they can also attract diseases and leach them
from the body. Charles Mackay, in Extraordinary Popular Delusions and
the Madness of Crowds (1841), says of Paracelsus that "his claim
to be the first of the magnetisers can scarcely be challenged."
But Paracelsus was also aware of the important role of the patient's
mind in the process of healing (Buranelli 1975). He wrote, "The
spirit is the master, the imagination is the instrument, the body is
the plastic material. The moral atmosphere surrounding the patient can
have a strong influence on the course of the disease. It is not the
curse or the blessing that works, but the idea. The imagination produces
the effect." Paracelsus was apparently well aware of the placebo
effect.
The development in eighteenth-century
England of carbon-steel permanent magnets more powerful than lodestones
brought renewed interest in the possible healing powers of magnets,
and among those interested was Maximilian Hell, a professor of astronomy
at the University of Vienna. Hell claimed several cures using steel
magnets, but he was rapidly eclipsed by a friend who borrowed his magnets
to treat a young woman suffering from a severe mental illness. The friend
was Franz Anton Mesmer (1734-1815), and Mesmer's success with the "magnets
from Hell" led directly to his widespread promotion of his theory
of "animal magnetism." Although he first used actual magnets,
he later found he could "magnetize" virtually anything --
paper, wood, leather, water -- and produce the same effect on patients.
He concluded that the animal magnetism resided in himself, the various
materials simply aiding the flow of the "universal fluid"
between him and the patients.
Mesmer became so successful in
Paris that in 1784 King Louis XVI established a Royal Commission to
evaluate the claims of animal magnetism, a commission that included
Antoine Lavoisier and Benjamin Franklin among its members. They conducted
a series of experiments and concluded that all the observed effects
could be attributed to the power of suggestion, and that "the practice
of magnetization is the art of increasing the imagination by degrees."
Thomas Jefferson, arriving in Paris soon after the Commission report,
noted in his journal: "Animal magnetism is dead, ridiculed."
Ridiculed, perhaps, but not dead.
Mesmer himself faded from public view, but "magnetizing" persisted
in various forms. Many early magnetizers evolved into students of hypnosis
and developed various forms of hypnotherapy. (The trance induced in
many of Mesmer's patients is thought to be what is now called a hypnotic
trance, and most dictionaries today list mesmerism as a synonym for
hypnotism.) One American who became interested in magnetic healing was
Daniel David Palmer, who opened Palmer's School of Magnetic Cure in
Iowa in the 1890s. His ideas developed into the system of hands-on therapy
known as chiropractic. Others focused on hand gestures without actual
touch, an approach recently reborn as "therapeutic touch."
[See "Catching Up With Eighteenth Century Science in the Evaluation
of Therapeutic Touch, " by Thomas S. Ball and Dean D. Alexander,
this issue, p. 31] Mary Baker Eddy was "cured" by a magnetizer,
but she later became convinced that cures could best be achieved through
prayer, and founded Christian Science.
Most of these byproducts of mesmerism,
like Mesmer himself, ceased to use actual magnets. But the development
of electrical technology in the late nineteenth century impressed the
general public with the mysterious powers of electric and magnetic fields,
and therapeutic magnets had a rebirth, with many "doctors"
promoting magnets to relieve pain, enhance sleep, and cure a wide variety
of diseases. The most notable of these was Dr. C. J. Thacher, whom Collier's
Magazine dubbed "King of the magnetic quacks" (Macklis 1993).
His 1886 mail-order catalogue offered a variety of magnetic garments,
and a complete costume contained more than 700 magnets, which provided
"full and complete protection of all the vital organs of the body."
In the twentieth century, materials
scientists and engineers have developed stronger and stronger permanent
magnets -- alnico magnets in the 1930s, ferrite (ceramic) magnets in
the 1950s, and rare-earth magnets in the 1970s and 1980s. The latest
rare-earth magnets, neodymium-iron-boron, are more than a hundred times
more powerful than the steel magnets available in the last century to
Edison, Bell, and C. J. Thacher (Livingston 1996). Both ferrite magnets
and the latest "neo" magnets have had a tremendous impact
on modern technology, but they have also restimulated interest in the
use of permanent magnets for magnetic therapy. Most magnetic therapy
products today, like most refrigerator magnets, contain inexpensive
ferrite magnets, but many suppliers offer neodymium "supermagnets"
in their top-of-the-line products.
Magnetic Therapy Today
Both ferrite and rare-earth magnets, unlike earlier magnetic materials
such as steels and alnicos, have great resistance to demagnetization,
allowing thin disks to be magnetized. (Earlier magnets had to be long
and thin to avoid being demagnetized by the internal fields produced
by the poles at the ends.) This feature allows modern magnets to be
mounted in a variety of thin products that can be applied to the body
with the magnetic field emanating from the surface.
Some suppliers recommend applying
magnetic patches directly to your aches and pains, while others recommend
applying small Band-Aid-like patches to acupuncture points. Magnetic
belts containing sixteen or more magnets are purported to ease back
pain, and similar magnetic wraps are offered for almost any part of
the body, including hands, wrists, elbows, knees, ankles, and feet (magnetic
insoles are particularly popular). For headaches you can wear magnetic
headbands, magnetic earrings, or magnetic necklaces. (One company marketing
magnetic necklaces provides simple instructions: the necklace should
be put on as soon as the headache appears and removed as soon as it
goes away. Since most headaches come and go, following these instructions
precisely will clearly produce persuasive evidence of the necklace's
efficacy.)
Many magnetic necklaces, bracelets,
and earrings are formed from silver- and gold-rich magnetic alloys and
promoted as both fashionable and therapeutic. One catalog claims magnetic
earrings "stimulate nerve endings that are associated with head
and neck pain," and magnetic bracelets "act upon the body's
energy field" and "correct energy imbalances brought by electro-magnetic
contamination or atmospheric changes." Larger items include magnetic
seat cushions, magnetic pillows, and magnetic mattress pads, the last
claiming to produce an "energizing sleep field." One supplier
offers a PCD -- Prostate Comfort Device for older men. If properly placed
while you sit watching television or driving your car, you will no longer
have to get out of bed several times a night to relieve yourself!
To avoid trouble with the Food
and Drug Administration, most suppliers emphasize only "comfort"
and usually specifically state "no medical claims are made."
Some, however, are far less careful. One company in Kansas markets a
book entitled Curing Cancer With Supermagnets. The authors of the book
claim to have cured cancer simply by hanging a neodymium "supermagnet"
around the patient's neck. The cancer discussed in the advertisement
was a breast cancer, but they report that "the supermagnets influence
the whole body" and "our method can cure all types of cancer."
Many magnetic therapy products
have alternating arrays of north and south poles facing the patient.
Some have detailed explanations of why a circular pattern of poles is
optimal, while others offer poles in checkerboard or triangular patterns.
Nikken, the Japan-based firm that has used a multilevel marketing scheme
to expand from an annual business in the U. S. of $3 million in 1989
to $150 million today, primarily offers products with alternating poles.
One clear difference between such
multipolar magnetic devices and unipolar devices (with only one pole
facing the patient) is the "reach" of the magnetic field.
The field from even unipolar magnets decreases very rapidly with increasing
distance from the magnet, but the field from multipolar magnets decreases
much more rapidly. If multipolar magnets really have any effects on
the human body, they will be limited to depths of penetration of only
a few millimeters. (Many refrigerator magnets are multipolar, which
limits the thickness of paper they can hold to the refrigerator, but
also limits the damage they can do to nearby credit and ATM cards.)
Other suppliers offer only unipolar
magnets, and some emphasize the importance of having only south-seeking
poles facing the body. Contrary to common scientific usage, they call
south-seeking poles north poles. Since opposite poles attract, they
argue that a pole that seeks south must be a north pole. (Here practitioners
of magnetic therapy are perhaps more logical than mainstream science,
which calls the south-seeking pole a south pole, requiring that the
earth's magnetic pole in Antarctica is, by the standard scientific terminology,
a north pole.) Dr. Buryl Payne, in his book The Body Magnetic (1988),
argues that south-seeking poles calm tissue but north-seeking poles
stimulate tissue, and you should therefore never expose tumors or infections
to north-seeking poles. When I suggested to one practitioner that different
effects from different poles seemed to violate basic rules of symmetry,
he assured me that the rules were reversed in the southern hemisphere.
One of the most ardent advocates
of magnetic therapy is Dr. William Philpott of Oklahoma, who publishes
his own Magnetic Energy Quarterly. He is also on the board of the Bio-Electro-Magnetics
Institute of Reno, Nevada, a nonprofit "research and educational
organization" and an advisor to the NIH Office of Alternative Medicine.
His wife happens to have a business selling "Polar Power Magnets."
Dr. Ronald Lawrence of California is President of the North American
Academy of Magnetic Therapy and reports that he has successfully used
magnets to relieve pain in hundreds of his patients. He is associated
with Magnetherapy, a Florida company that markets "Tectonic Magnets."
Both Dr. Philpott and Dr. Lawrence favor unipolar magnets.
The efficacy of magnetic therapy
(or of any other medical treatment, mainstream or alternative) does
not depend on our understanding the biological mechanism. Nevertheless
most promoters of magnetic therapy recognize the need for offering some
plausible explanation. The mechanism most commonly offered for various
therapeutic effects of magnets is improved blood circulation, despite
a lack of clear evidence for such an effect. Other suggestions include
alteration of nerve impulses, increased oxygen content and increased
alkalinity of bodily fluids, magnetic forces on moving ions, and decreased
deposits on the walls of blood vessels.
The broadest explanation was presented
by Dr. Kyochi Nakagawa of Japan, who claims that many of our modern
ills result from "Magnetic Field Deficiency Syndrome." The
earth's magnetic field is known to have decreased about 6 percent since
1830, and indirect evidence suggests that it may have decreased as much
as 30 percent over the last millennium. He argues that magnetic therapy
simply provides some of the magnetic field that the earth has lost.
Magnetic therapy is also prominent
in the treatment of thoroughbred racehorses. An injured racehorse represents
potential loss of a substantial investment, providing considerable incentive
to try "alternative medicine" to supplement mainstream veterinary
treatment. Magnetic pads for a variety of leg problems, magnetic blankets,
magnetic hoof pads, etc., all get ringing endorsements from many horse
trainers -- and even some veterinarians. One marketer of magnetic products
for humans reports that he first became convinced of their effectiveness
when he used them on his ailing llama! Enthusiasts argue that the placebo
effect could not be effective on horses or other animals, but forget
that it may influence the human who is interpreting the effect of magnetic
therapy on the animal.
The Baylor Study
These examples and the centuries-old
connection between magnets and quackery, have led many to consider modern
magnetic therapy as total hokum, with the many testimonials for the
success of magnetic treatments explainable by placebo effects. But the
Baylor study, seemingly a careful double-blind study, has surprised
many.
The study was conducted by Dr.
Carlos Vallbona on fifty post-polio patients at Baylor's Institute for
Rehabilitation Research in Houston. Bioflex, Inc., of Corpus Christi
provided both the magnets (multipolar, circular pattern) and a set of
visually identical sham magnets to serve as controls. To keep the study
"double-blind" neither the patients nor the staff were informed
as to which devices were active magnets, and which were shams. Before
and after the forty-five-minute period of magnet therapy, the patients
were asked to grade their pain on a scale from 0 to 10. The twenty nine
patients with active magnets reported, on average, a significant reduction
of pain (from 9.6 to 4.4), while the twenty-one patients with shams
reported a much smaller average reduction (from 9.5 to 8.4). This is
a substantial difference, and if the double-blind study was successfully
conducted, cannot be explained by a placebo effect.
For a hardened skeptic, some doubts
remain. Both Dr. Vallbona and his colleague, Dr. Carlton Hazlewood,
had reported the successful personal use of magnets to relieve their
own knee pains prior to the study, raising doubts as to their objectivity.
Conscious or unconscious biases of researchers can have very subtle
and unrecognized effects on the results of their studies, and a serious
difficulty of conducting any double-blind studies with magnets is the
ease of distinguishing active magnets from sham magnets (although the
patients were reportedly observed during the therapy period to assure
that they were not surreptitiously testing their magnets). Another difficulty
of any studies of pain relief is the highly subjective nature of the
data.
Despite these various reasons for
caution, the results of this study have altered the views of many physicians.
Dr. William Jarvis, president of the National Council Against Health
Fraud, had formerly dismissed magnet therapy as "essentially quackery."
He now tentatively admits that it may have value for post-polio pain.
More studies will be needed before
magnetic therapy will be accepted by a majority of the medical community,
and some studies are already underway. Last year the NIH Office of Alternative
Medicine gave a million-dollar grant to Dr. Ann Gill Taylor of the School
of Nursing of the University of Virginia to study the use of magnets
to relieve pain. Among other things, she will be testing the effectiveness
of magnetic sleep pads in relieving pain in patients suffering from
fibromyalgia, a common disease involving joint and muscle pain. While
we wait for the results of these and other studies, does what we know
about magnetic fields and the human body make it plausible that magnetic
therapy for pain might have a physical basis beyond mind/body effects?
Magnetic Fields and the Body
The electrochemical processes of the human body are extremely complex
and incompletely understood, and physical effects of magnetic fields
cannot be ruled out. Many thousands of papers have in fact been published
on biological effects of electromagnetic fields, much of it focused
on the effects of radio-frequency and microwave fields or, in recent
years, on fields at power-line frequencies (fifty or sixty cycles per
second). Studies of biological effects of steady magnetic fields (reviewed
by Frankel and Liburdy 1996) have concentrated mostly on high fields
of the level encountered in MRI magnets, typically of the order of 10,000
gauss (1 tesla). Unfortunately, research has been very limited at field
levels typical of magnetic therapy products, most of which are limited
to a few hundred gauss, even at the magnet surface. (The earth's field
is a bit less than half a gauss.)
Viewed simply as inert material,
the human body, like its primary constituent, water, is diamagnetic,
i.e., weakly repelled by magnetic fields. In response to an applied
magnetic field, the electrons in water molecules make slight adjustments
in their motions, producing a net magnetic field in the opposing direction
about 100,000 times smaller than the applied field. With the removal
of the applied field, the electrons return to their original orbits,
and the water molecules once again become nonmagnetic. (We perhaps should
note that some promoters of magnetic therapy also promote "magnetized
water." You can't magnetize water. Although water responds weakly
to an applied field, the response disappears as soon as the field is
removed.) Although the diamagnetism of water and most living things
is very weak, a high-field electromagnet producing 160,000 gauss (16
tesla) at the center of the coil has recently been used to levitate
not only water drops but also flowers, grasshoppers, and small frogs
(Berry and Geim 1997), the "flying frogs" drawing worldwide
media coverage. Since fields of that magnitude are required to balance
gravitational forces, the much lower fields of magnetic-therapy devices
can only produce diamagnetic forces that are thousands of times smaller
than gravity. (The repulsive force will be proportional to the product
of the field and the field gradient.)
Some dubious literature suggests
that magnetic fields attract blood, citing all the iron it contains.
However, iron in the blood is very different from metallic iron, which
is strongly magnetic because the individual atomic magnets are strongly
coupled together by the phenomenon we call ferromagnetism. The remarkable
properties of ferromagnetic materials are a result of the cooperative
behavior of many, many magnetic atoms acting in unison. The iron in
blood consists instead of isolated iron atoms within large hemoglobin
molecules, located inside the red blood cells. Although each of the
iron atoms is magnetic, it is not near other iron atoms, and remains
magnetically independent.
The net effect of the weak paramagnetism
of the isolated iron atoms in hemoglobin is only a slight decrease in
the overall diamagnetism of blood. Blood, like water, is weakly repelled
by magnetic fields, not attracted.
Although most components of the
human body and other living things are weakly diamagnetic, many organisms
have been shown to contain small amounts of strongly magnetic materials,
usually magnetite (Fe3O4). The most extreme case is that of magnetotactic
bacteria, originally found in mud collected from the marshes of Cape
Cod. Each contains a long chain of magnetite particles that interact
strongly enough with the earth's magnetic field to orient the bacteria
along the field. Magnetite crystals have also been found in pigeons,
honeybees, many mammals, and even in the human brain, but in proportionately
much smaller amounts than in the bacteria. It seems very unlikely that
there is enough magnetite within the human body to provide a possible
mechanism to explain magnetic therapy. However, if magnetite particles
were located at strategic places, they could locally amplify the effects
of low magnetic fields and, for example, modify ion flow across cell
membranes, of the type involved with electrical transmission in nerve
cells.
More likely mechanisms are those
based on magnetic forces on moving charged particles, possibly including
ions or charged molecules in flowing blood, moving across cell membranes,
moving across synapses between nerve cells, etc., or those based on
more subtle effects on biochemical reactions (Frankel and Liburdy 1996).
Although no physical mechanisms for magnetic therapy have been established,
the possibilities are numerous and complex. Only further clinical tests,
carefully controlled to account for placebo effects, can confirm or
dispute the results of the Baylor study and prove or disprove the claims
of magnetic therapy.
Some media reports have not sufficiently
distinguished the Baylor form of magnetic therapy, based on modest static
fields from permanent magnets, with a more accepted form of "magnetic
therapy" based on high pulsed magnetic fields from electromagnets
(Malmivuo and Plonsey 1995). Pulsed magnetic fields are very different
from static magnetic fields, because, via Maxwell's equations, time-varying
magnetic fields induce electric fields. Electric fields have pronounced
biological effects, particularly on nerve and muscle cells, as we have
known since the days of Galvani and his twitching frogs' legs. Many
years ago the FDA approved the use of pulsed magnetic fields in "bone
growth stimulators" for the treatment of fractures that were slow
to heal, and research on "magnetic stimulation" -- pulsed
magnetic fields applied to the brain or other components of the nervous
system -- has grown rapidly in recent years. Transcranial magnetic stimulation,
in which the patient receives hundreds of magnetic field pulses of 1
tesla or more, each only a millisecond in duration, has shown considerable
promise as a means of treating depression. However, these forms of pulsed-field
magnetic therapy are based on biological effects of induced electric
fields, and are very different from the use of the static fields from
permanent magnets.
Conclusions
Claims of therapeutic effects of permanent magnets should still be regarded
with considerable skepticism. Most of the many testimonials to the effectiveness
of magnetic therapy devices can be attributed to placebo effects and
to other effects accompanying their use. For example, the magnetic back
braces used by many senior golfers may help ease their back pains through
providing mechanical support, through localized warming, and through
constant reminder to the aging athletes that they are no longer young
and should not overexert their muscles. All these effects are helpful
with or without magnets. One British study of pulsed-field bone-growth
stimulators, which were approved decades ago by the FDA, found that
they were equally successful when the devices were not activated (Barker
1984), and concluded that their effectiveness resulted from the enforced
inactivity associated with their use, rather than from the pulsed magnetic
fields.
The more extreme claims of magnetic
therapy, such as curing cancer by hanging supermagnets around your neck,
are not only nonsense but also dangerous, since they may divert patients
from seeking appropriate treatment from mainstream medicine. Magnetic
jewelry and most other magnetic-therapy products probably are harmless
beyond a waste of money. Several years ago, a double-blind study found
that magnetic necklaces produced no relief of neck or shoulder pain
(Hong 1982).
The results of the Baylor study,
however, raise the possibility that at least in some cases, topical
application of permanent magnets may indeed be useful in pain relief,
a conclusion that should be regarded as tentative until supported by
further studies. Any mechanism for such an effect remains mysterious,
but an effect of static magnetic fields on the complex electrochemical
processes of the human body is not impossible. My own guess is that
inexpensive refrigerator magnets are as likely to provide help as the
more expensive magnets marketed specifically for therapy. (But since
human nature leads us to expect more from more expensive items, use
of refrigerator magnets will probably decrease the placebo effect!)
References
* Barker, A. T. et al. 1984. Pulsed
magnetic field therapy for tibial non-union. Lancet 994-996.
* Berry, M. V. and A. K.
Geim. 1997. Of flying frogs and levitrons. Eur. J. Phys. 18: 307-313.
* Buranelli, V. 1975. The Wizard from Vienna. Coward, McCann & Geoghegan.
* Frankel, Richard B. and Robert P. Liburdy. 1996. Biological effects
of static magnetic fields (in Handbook of Biological Effects of Electromagnetic
Fields, second edition, Charles Polk and Elliot Postow, eds. CRC Press).
* Hong, C. Z. et al. 1982. Magnetic necklace: Its therapeutic effectiveness
on neck and shoulder pain. Archives of Physical Medicine and Rehabilitation
63:162-164.
* Livingston, James D. 1996. Driving Force: The Natural Magic of Magnets.
Harvard University Press.
* Mackay, Charles. [1841] 1932. Extraordinary Popular Delusions and
the Madness of Crowds. Reprint, L. C. Page.
* Macklis, Roger M. 1993. Magnetic healing, quackery, and the debate
about the health effects of electromagnetic fields. Annals of Internal
Medicine 118(5): 376-383.
* Malmivuo, Jaakko and Robert Plonsey. 1995. Bioelectromagnetism: Principles
and applications of bioelectric and biomagnetic fields. Oxford University
Press.
* Payne, Buryl. 1988. The Body Magnetic (self-published).
* Vallbona, Carlos, Carlton F. Hazlewood, and Gabor Jurida. 1997. Response
of pain to static magnetic fields in postpolio patients: A double-blind
pilot study. Archives of Physical and Rehabilitation Medicine 78(11):
1200-1203.
About the Author
James D. Livingston now teaches in the Department of Materials Science
and Engineering at the Massachusetts Institute of Technology, and was
for more than thirty years a physicist at General Electric's Corporate
Research and Development Center. He is the author of Driving Force:
The Natural Magic of Magnets (Harvard, 1996), a popular-science book
on the history, legends, science, and technology of magnets. |